Digital Voice Systems VC-20-PRJ25, User Manual

Page 1: ...VC 20 PRJ25 IMBE Vocoder Board User s Manual Version 2 0 Digital Voice Systems Inc The Speech Compression Specialists...

Page 2: ...espect to the documentation and disclaims any implied warranties of merchantability and fitness for a particular purpose Digital Voice Systems Inc shall not be liable for any errors or for incidental...

Page 3: ...r Board 2 3 Transfer of License a END USER may transfer the IMBE Software and all rights under this agreement to a third party together with a copy of this Agreement provided that END USER provides DV...

Page 4: ...xclusion of implied warranties so the above exclusion may not apply to END USER No oral or written information or advice given by DVSI or its employees shall create a warranty or in any way increase t...

Page 5: ...shall be enforced to the maximum extent permissible and the remaining provisions of this Agreement shall remain in full force and effect 12 0 Notices 12 1 Any notices to DVSI which may be given hereun...

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Page 7: ...R SIGNAL DESCRIPTIONS 6 Section 4CHAPTER 2 TECHNICAL DRAWINGS 10 Section 5CHAPTER 3 DVSI SUPPORT SERVICES 16 TECHNICAL SUPPORT 16 LIST OF FIGURES Figure 1 Silence Voice Frame Signaling 9 Figure 2 VC 2...

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Page 9: ...acceptance of these licensing terms The VC 20 PRJ25 operates by digitizing an analog speech signal using an on board A to D converter This digitized speech is then processed by the encoder and convert...

Page 10: ...SD and LOST Note if soft decision information is unavailable then the HD_SD signal should be held high or left unconnected so that only the MSB data signals QRXD IRXD will be read by the decoder The f...

Page 11: ...dBm0 0 dBm Sinusoidal Overload 3 17 dBm0 Nominal Level 23 dBm0 average speech level Dynamic Range 10 dB relative to Nominal Level Noise Level 72 dBm0 Analog Output Type single ended Impedance low impe...

Page 12: ...ND 14 Reserved Reserved Reserved 15 Output RESET Reserved Input DINRS 16 Output STATUS Reserved Reserved 17 Output ENSLNCE Reserved Reserved 18 Input IRXD1 Reserved Input QRXD1 19 Input IRXD0 Reserved...

Page 13: ...Receive data Q channel MSB QRXD1 Input Receive data Q channel QRXD0 Input Receive data Q channel LSB RXCK Input Receive data bit clock 3 6 kHz FMDE Input Decoder frame flag Active High LOST Input Los...

Page 14: ...ently ENSLNCE is never active FMEN Silence Voice Voice Voice Silence ENSLNCE Figure 1 Voice Silence Detection Timing FEC_OFF The FEC_OFF signal can be pulled low to disable all error correction and in...

Page 15: ...nvalid in which case the decoder ignores the current frame of channel data and performs a frame repeat This flag is only monitored during the first clock period of each frame RESET The RESET signal is...

Page 16: ...e signals combined with the in phase data signals result in a total data rate of 7 2 kbps STATUS The STATUS flag indicates the status of the voice codec During normal operation the voice codec sets th...

Page 17: ...K 2 Connects on board 3 6 kHz data clock to RXCK 3 Connects on board 20 ms frame clock to FMEN 4 Connects on board 20 ms frame clock to FMDE 5 Connects ITXD to IRXD0 LSB 6 Connects ITXD to IRXD1 7 Con...

Page 18: ...tary Chapter 2 Technical Drawings Figure 2 Vocoder Connections in Loop back Mode ITXD TXCK FMEN ENSLNCE FMDE DESLNCE IRXD IRXD1 IRXD0 RXCK LOST ENCODER DECODER On Board Clock Frame Generator VFXI VFRO...

Page 19: ...Drawings DVSI Confidential Proprietary Note Not meant to represent an off the shelf modem ITXD QTXD TXCK FMEN FMDE DESLNCE QRXD QRXD1 QRXD0 RXCK LOST ENCODER DECODER MODEM Figure 3 Connections betwee...

Page 20: ...DER 2 DECODER 2 Figure 4 Dual Vocoder Connections ENCODER 1 DECODER 1 On Board Clock Frame Generator 1 FMEN TXCK LOST FMEN TXCK FMDE RXCK ITXD QTXD DESLNCE On Board Clock Frame Generator 2 VFXI VFRO V...

Page 21: ...3 Section 4 Technical Drawings DVSI Confidential Proprietary Figure 5 Channel Interface Timing Relationships TXXK FMEN QTXD ITXD 500 ns RXCK FMDE QRXD IRXD LOST DESLNCE HD_SD 500 ns 20 ms 1 rate secon...

Page 22: ...VC 20 PRJ25 IMBE Vocoder Board User s Manual Page 14 Section 4 Technical Drawings DVSI Confidential Proprietary RUN 12 5ms 20ms Figure 6 RUN Signal Timing 7 5ms Encoder Window Decoder Window...

Page 23: ...anual Page 15 Section 4 Technical Drawings DVSI Confidential Proprietary Figure 7 Vocoder Physical Dimensions bottom view 3 0 mm 5 5 mm 41612 Connector 112 mm 100 mm 7 5 mm side view 11 mm 7 5 mm 112...

Page 24: ...pter 3 DVSI Support Services Technical Support If you have any problems with the VC 20 PRJ25 IMBE Vocoder Board or have questions about its operation please contact Digital Voice Systems Inc 234 Littl...

Page 25: ...Page 17 DVSI Confidential Proprietary NOTES...